Last week's updates prompt support complaints; problem first reported in December

Updates that Microsoft Corp. began feeding Windows Vista users last week to prep PCs for next month's release of Service Pack 1 (SP1) have crippled some machines, according to messages posted to the company's support site.

Microsoft said it is investigating the reports.

Last Tuesday, Microsoft started sending Vista users two final prerequisite updates that are required before SP1 can be installed in March. The updates to the operating system's install components were delivered via Windows Updates, which automatically downloaded and installed them on the majority of Vista machines.

Users quickly started squawking.

In most cases, they reported that the final update hung while displaying the message "Configuring Updates Step 3 of 3 -- 0% Complete," which was followed by a reboot of the PC. Which was followed by another reboot, and another. "[It] reboots ad infinitum," said Frank Melk on the Microsoft support newsgroup. A smaller number reported a different problem: After the update, their computer refused to boot normally.

Trying to boot into Safe Mode did no good, users said; the reboot loop cranked up then as well. "I am unsure as to what to do, because entering Safe Mode gives the same screen," Melk said. "Furthermore, I have no restore points saved, so going back to a known previous good config is no good either!"

Melk's mention of restore points referred to Windows Vista's System Restore, a tool that periodically takes a "snapshot" of the PC. Also called restore points, they can be called up to return the machine to its condition at the time the snapshot was taken. Some users who posted messages to the same newsgroup said that they had managed to regain control of the computer by booting from their Vista install DVD and selecting the "Restore from a previous restore point" option.

"The first two restore points available to me failed," noted another user, pegged as phazedoubt. "I had to go back three days before I found one that worked."

Others said they had been in touch with Microsoft support representatives -- the company offers free support to consumers on all update issues through a toll-free number (866) 727-2338 or e-mail -- and claimed that they had been told to boot from their Vista media and choose "Run Startup Repair."

"Apparently, so Microsoft says, my machine was restarted thinking it had downloaded an update, but really the update hadn't been downloaded," said user bicksbah on the support newsgroup. "So, upon reboot, it couldn't find the update and Vista kept trying to install it endlessly."

Microsoft was aware of the problem by late Friday, when someone identified as Darrell Gorter, who claimed to be with the company, asked users to send him log files "to determine a cause for the issue." On Monday, however, a company spokeswoman had little more to offer. "We are currently looking into this but have no additional information to share at this time," she said. "We apologize for any inconvenience this may be causing our users."

Messages left on support newsgroups, in fact, show that the problem was first reported by users in December when Microsoft offered a Vista SP1 release candidate to the general public, but required them to download and install the prerequisite updates manually, one after the other. The complaint volume picked up last month when Microsoft opened a second, more finished, build to all comers.

Some users remained frantic because they did not have a Vista install or recovery disc; computer makers often forgo such niceties, instead putting the recovery files on the PC's hard drive. Others took Microsoft to the woodshed.

"What blows me away is that Microsoft has not posted anything on the site yet, at least nothing I could find," said redwinger in a message to the newsgroup on Sunday. "They should at least say, 'We know we have an issue and we are looking into it.' I bought the laptop with the OS loaded and I don't have the recovery disk. How screwed am I?"

Although it's impossible to gauge the extent of the prerequisite reboot problem from the support forums, the traffic on the Windows Vista Service Pack 1 (SP1) newsgroup is substantial: the thread to which Melk, Gorter and phazedoubt posted included nearly 80 messages by midday Sunday, and had been viewed more than 23,000 times.

Two weeks ago, Microsoft announced it had completed SP1, and was sending it to resellers for installation on new computers, and to duplication to prep retail copies. At the same time, however, it said it would not make it available to most users until mid-March, and would not deliver it automatically via Windows Update until April.